Improvement in alarm-locks



' e. W. GRAHAM.

ALARM-LOCK.

No. 191,046. Patents c1 May 22,1877.

NPEI'ERS, FHOTD-LITNDGRAPNER. WASHINGTON, D C

slides in horizontal, the other bolt or bar, F

QFFIC.

GEORGE W. GRAHAM, OF GRAND JUNCTION, TENNESSEE.

IMPROVEMENT IN ALARM-LOCKS.

Specification forming part of Letters Patent No.

191,046, dated May 22, 1877; application filed April 16, 1877.

To an whom it may concern Be it known that l, GEORGE W. GRAHAM, of Grand Junction, in the county of Hardeman and State of Tennessee, have invented a new and Improved Look, of which the following is a specification:

In the accompanying drawing, Figure 1 represents a side elevation of my improved lock-with parts cut off; Fig. 2, a horizontal section of the same on line a: m, Fig. l; and Fig. 3, a detail view of the additional key required.

Similar letters of reference indicate corresponding parts.

. The object of this invention is to provide an improved combination bar and bolt-lock, that secures the door in strong and reliable manner and the invention consists of toothed bolts, moving at right angles to each other when engaged by a cog-wheel turned by a' key after the common spring-bolt is withdrawn. The vertical bolt lifts the cross-bar and rings a hell on opening.

In the drawing, A represents a door, which is provided with a lock, B, and a strong crossbar, 0, that serve jointly to lock the same.

The lock B is provided with a common knob-bolt and knob, D, in the customary manner, for the purpose of opening and closing the lock for common use during the day.

A cog-wheel, E, of the lock is turned by a suitable key, E, fitting on the square centerpivot of the same, and is made to gear with the toothed bolts F F, of which the .bolt F in vertical, direction, they being both guided in suitable manner in the lock-casing.

The cog-wheel E is so placed near the point of crossing of the bolts F F that both are ongaged at the same time, one being drawn back and theother lifted, so as to withdraw bolt F from its retaining-plate F and raise cross-bar C out of the upper part of the plate F high enough to clear the same, for admitting the opening of the door.

The horizontal bolt F is provided with re- 1' cesses a, into which an ordinary key-bolt, G, locks, for retaining the bolt in open as well as closed position, the key-bolt G retaining, at the same time, the upright bolt F in raised or lowered position by means of the intermeshing cog-wheel E.

The lifting bolt or bar F is connected, by a sliding and spring-acted joint, with a bell device, H, that is operated simultaneously with the opening of the bolts, so as to give a bellsignal.

The lock and cross bar are operated in easy manner by two keys-a common key for withdrawing the key-bolt G, and a second key, E, for operating jointly the lock-bolt F and cross-bar lifting-bolt F The cross-bar O is hung by an end hole to a staple, b, of the door-casing, to swing readily thereon when raised.

When the bolt F is drawn back and the cross-bar lifted the key-bolt is dropped into the second recess, a, of bolt F, so as to retain the bolts in open position. The door is locked and barred from the outside by the two keys, and thereby a strong and efl'ective, yet simple and quickly-operated, lock construction furnished.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. The combination of toothed bolts F F arranged at right angles to each other, with an operating cog-wheel, E, and crossbar O, for simultaneously Withdrawing or looking bolt F and raising or lowering cross-bar G, substantially as and for the purpose set forth.

2. The combination of the toothed bolt F,

having recess a, and toothed upright bolt F, 

